Simulated Tumor Microenvironment Research Articles

Antisense oligonucleotide facilitate the photothermal therapy of Mxene-based nanoplatform for drug-resistant breast cancer

Breast cancer has become the most common form of cancer worldwide. Chemotherapy failure, primarily due to drug resistance, necessitates the development of new therapeutic strategies. In this study, ultrathin Ti3C2 nanosheets are utilized as photothermal agents and nanocarriers. We developed a multifunctional Ti3C2-based nanoplatform (214.7 nm) through layer-by-layer absorption of HSP90 antisense oligonucleotide (ASO) and doxorubicin (DOX), with surface modification using hyaluronic acid (HA). In a simulated acidic tumor microenvironment in vitro, 90 % of the drug was released within 36 hours. Additionally, Under 808 nm irradiation (2.0 W/cm²), MCF-7/ADM cell viability assays revealed the following results: HA-Ti3C2 (57 %), HA-Ti3C2@ASO (HT@A) (41 %), and HA-Ti3C2@ASO/DOX (HT@AD) (26 %), which shown the synergistic inhibitory effects of this multifunctional nanoplatform. Herein, this nanosystem exhibits enhanced biocompatibility, superior photothermal performance, and stimuli-responsive drug release behavior, making it a promising candidate for effective inhibition of cancer cell proliferation and migration.

A DNA Molecular Logic Circuit for Precise Tumor Identification.

Tumor-associated antigens (TAAs) are not exclusively expressed in cancer cells, inevitably causing the "on target, off tumor" effect of molecular recognition tools. To achieve precise recognition of cancer cells, by using protein tyrosine kinase 7 (PTK7) as a model TAA, a DNA molecular logic circuit Aisgc8 was rationally developed by arranging H+-binding i-motif, ATP-binding aptamer, and PTK7-targeting aptamer Sgc8c in a DNA sequence. Aisgc8 output the conformation of Sgc8c to recognize PTK7 on cells in a simulated tumor microenvironment characterized by weak acidity and abundant ATP, but not in a simulated physiological environment. Through in vitro and in vivo results, Aisgc8 demonstrated its ability to precisely recognize cancer cells and, as a result, displayed excellent performance in tumor imaging. Thus, our studies produced a simple and efficient strategy to construct DNA logic circuits, opening new possibilities to develop convenient and intelligent precision diagnostics by using DNA logic circuits.

Biomimetic Dual-Target Theranostic Nanovaccine Enables Magnetic Resonance Imaging and Chemo/Chemodynamic/Immune Therapy of Glioma.

Development of theranostic nanomedicines to tackle glioma remains to be challenging. Here, we present an advanced blood-brain barrier (BBB)-crossing nanovaccine based on cancer cell membrane-camouflaged poly(N-vinylcaprolactam) (PVCL) nanogels (NGs) incorporated with MnO2 and doxorubicin (DOX). We show that the disulfide bond-cross-linked redox-responsive PVCL NGs can be functionalized with dermorphin and imiquimod R837 through cell membrane functionalization. The formed functionalized PVCL NGs having a size of 220 nm are stable, can deplete glutathione, and responsively release both Mn2+ and DOX under the simulated tumor microenvironment to exert the chemo/chemodynamic therapy mediated by DOX and Mn2+, respectively. The combined therapy induces tumor immunogenic cell death to maturate dendritic cells (DCs) and activate tumor-killing T cells. Further, the nanovaccine composed of cancer cell membranes as tumor antigens, R837 as an adjuvant with abilities of DC maturation and macrophages M1 repolarization, and MnO2 with Mn2+-mediated stimulator of interferon gene activation of tumor cells can effectively act on both targets of tumor cells and immune cells. With the dermorphin-mediated BBB crossing, cell membrane-mediated homologous tumor targeting, and Mn2+-facilitated magnetic resonance (MR) imaging property, the designed NG-based theranostic nanovaccine enables MR imaging and combination chemo-, chemodynamic-, and imnune therapy of orthotopic glioma with a significantly decreased recurrence rate.

Codonopsis pilosula-derived glycopeptide dCP1 promotes the polarization of tumor-associated macrophage from M2-like to M1 phenotype

The majority of the immune cell population in the tumor microenvironment (TME) consists of tumor-associated macrophages (TAM), which are the main players in coordinating tumor-associated inflammation. TAM has a high plasticity and is divided into two main phenotypes, pro-inflammatory M1 type and anti-inflammatory M2 type, with tumor-suppressive and tumor-promoting functions, respectively. Considering the beneficial effects of M1 macrophages for anti-tumor and the high plasticity of macrophages, the conversion of M2 TAM to M1 TAM is feasible and positive for tumor treatment. This study sought to evaluate whether the glycopeptide derived from simulated digested Codonopsis pilosula extracts could regulate the polarization of M2-like TAM toward the M1 phenotype and the potential regulatory mechanisms. The results showed that after glycopeptide dCP1 treatment, the mRNA relative expression levels of some M2 phenotype marker genes in M2-like TAM in simulated TME were reduced, and the relative expression levels of M1 phenotype marker genes and inflammatory factor genes were increased. Analysis of RNA-Seq of M2-like TAM after glycopeptide dCP1 intervention showed that the gene sets such as glycolysis, which is associated with macrophage polarization in the M1 phenotype, were significantly up-regulated, whereas those of gene sets such as IL-6-JAK-STAT3 pathway, which is associated with polarization in the M2 phenotype, were significantly down-regulated. Moreover, PCA analysis and Pearson's correlation also indicated that M2-like TAM polarized toward the M1 phenotype at the transcriptional level after treatment with the glycopeptide dCP1. Lipid metabolomics was used to further explore the efficacy of the glycopeptide dCP1 in regulating the polarization of M2-like TAM to the M1 phenotype. It was found that the lipid metabolite profiles in dCP1-treated M2-like TAM showed M1 phenotype macrophage lipid metabolism profiles compared with blank M2-like TAM. Analysis of the key differential lipid metabolites revealed that the interconversion between phosphatidylcholine (PC) and diacylglycerol (DG) metabolites may be the central reaction of the glycopeptide dCP1 in regulating the conversion of M2-like TAM to the M1 phenotype. The above results suggest that the glycopeptide dCP1 has the efficacy to regulate the polarization of M2-like TAM to M1 phenotype in simulated TME.

Comparison of Surgical and Colonoscopy Tissue to Establish Colorectal Patient-derived Organoids.

Patient-derived organoids (PDOs) are ex vivo models that retain the functions and characteristics of individualized source tissues, including a simulated tumor microenvironment. However, the potential impact of undiscovered differences between tissue sources on PDO growth and progression remains unclear. This study aimed to compare the growth and condition of PDO models originating from surgical resection and colonoscopy and to provide practical insights for PDO studies. Tissue samples and relevant patient clinical information were collected to establish organoid models. PDOs were derived from both surgical and colonoscopy tissues. The growth of the organoids, including their state, size, and success rate of establishment, was recorded and analyzed. The activity of the organoids at the end stage of growth was detected using calcein-AM fluorescence staining. The results showed that the early growth phase of 2/3 colonoscopy-derived organoids was faster compared to surgical PDOs, with a growth difference observed within 11-13 days of establishment. However, colonoscopy-derived organoids exhibited a diminished growth trend after this time. There were no significant differences observed in the terminal area and quantity between the two types of tissue-derived organoids. Immunofluorescence assays of the PDOs revealed that the surgical PDOs possessed a denser cell mass with relatively higher viability than colonoscopy-derived PDOs. In the establishment of colorectal patient-derived organoids, surgically derived organoids require a slightly longer establishment period, while colonoscopy-derived organoids should be passaged prior to growth inhibition to preserve organoid viability.

Synthesis and characterization of the redox-responsive amphiphilic fluorescent alginate derivatives as the multi-functional hydrophobic anticancer drug delivery system with visualization and sustained release

To develop the multi-functional hydrophobic anticancer drug carriers with visualization and sustained release, a novel amphiphilic alginate derivative (LSA-SS-DEAC) containing chromophobe groups was designed and synthesized by grafting hydrophobic fluorescent molecule, 7-(diethylamino-coumarin-3-carboxylic acid (DEAC-COOH) onto hydrophilic low molecular alginate backbone through cystamine by water-soluble carbodiimide chemical method. The molecular structure and self-assembly properties of the synthesized LSA-SS-DEAC were characterized. Furthermore, the encapsulation of anti-cancer drugs, doxorubicin hydrochloride (DOX) in LSA-SS-DEAC self-assembled micelles was realized by ultrasonic dialysis method. Subsequently, the in vitro drug release behavior and in vitro cytotoxicity of LSA-SS-DEAC micelles in simulated tumor microenvironment were also studied. The resultant LSA-SS-DEAC with the critical micelle concentration (CMC) of 0.26 mg/mL exhibited the ability to spontaneously form spherical micelles with the particle size of 250.2 ± 4.3 nm (PDI = 0.23) and zeta potential of −49.1 ± 0.4 mV, which presented good stability in pH 7.4 PBS and excellent fluorescence properties and redox responsiveness. The drug-loaded LSA-SS-DEAC micelles had the optimal EE value of about 42.2% when the DOX/LSA-SS-DEAC mass ratio was 3:10. Meanwhile, The drug-loaded LSA-SS-DEAC micelles exhibited sustained release in GSH-free environment, and the cumulative drug release rates were 40.3% and 46.6% in pH 7.4 and 5.0 PBS for 48 h, respectively. However, in the simulated tumor cell microenvironment (pH 5.0 PBS + 10 mM GSH), the disulfide bond between the core-shell was broken under the GSH trigger, and the LSA-SS-DEAC micelles collapsed, resulting in a cumulative drug release rate of about 64% at 12 h. In vitro cytotoxicity results showed that LSA-SS-DEAC had low cytotoxicity, and revealed obvious inhibitory effect on HeLa cells after DOX loading. Fluorescence imaging results indicated that LSA-SS-DEAC micelles could emit green light after ingested by cells, and their fluorescence properties were not affected after encapsulation of DOX. Accordingly, LSA-SS-DEAC micelles had the potential for drug localization tracking and rapid drug release at focal sites, which could be expected to be an ideal drug carriers for hydrophobic anticancer drug delivery.

Unveiling a pH-Responsive Dual-Androgen-Blocking Magnetic Molecularly Imprinted Polymer for Enhanced Synergistic Therapy of Prostate Cancer.

Prostate cancer is the most common malignancy diagnosed in men. Androgens are directly related to its pathogenesis. Inhibition of the androgen receptor (AR) is considered to be the most promising therapeutic approach for the treatment of prostate cancer. In this study, a new type of pH-responsive dual androgen-blocking nanodrug (FASC MIPs) based on a molecularly imprinted polymer has been designed and synthesized. The nanodrug could selectively sequester testosterone from the prostate tumor through specific molecular imprinting sites and simultaneously deliver the AR inhibitory drug bicalutamide, which ultimately leads to enhanced synergistic therapy of prostate cancer. FASC MIPs demonstrate excellent pH responsiveness in a simulated tumor microenvironment due to the presence of chitosan and significantly inhibit the growth of prostate cancer cells (LNCaP cells) by blocking the G1 phase of cytokinesis. Additionally, the nanodrug also displayed excellent antitumor properties in a xenograft mouse model of prostate cancer without any sign of detrimental effects on healthy tissues and organs. Both in vitro and in vivo studies verified the augmented and synergistic therapeutic effects of FASC MIPs, and the proposed dual-androgen-blocking strategy could explore novel avenues in prostate cancer treatment.

Human papillomavirus infection affects the immune microenvironment and antigen presentation in penile cancer.

Penile squamous cell carcinoma (PSCC) is a largely neglected condition, predominantly affecting underdeveloped regions, and is associated with risk factors such as low socioeconomic status, phimosis, and human papillomavirus (HPV) infection. Unlike other urogenital cancers, its pathophysiology and therapeutic targets remain poorly understood, particularly regarding the immune response to the tumor microenvironment. This study aims to investigate immune cell infiltration profiles, dendritic cell maturation, and lymphocyte apoptosis in both HPV-positive and HPV-negative PSCC. Clinical and histopathological data, along with peripheral blood and tumor tissue samples, were collected from 30 patients (66.6% were HPV-positive and 33.3% HPV-negative), with an additional 19 healthy donors serving as controls. Tumor-infiltrating immune cells were analyzed following enzymatic digestion of tumor tissue, enabling detailed phenotypic characterization. A simulated tumor microenvironment was created using supernatants derived from primary cultures of HPV-positive PSCC tumors. Peripheral blood mononuclear cells were isolated and differentiated into dendritic cells (Mo-DCs) for further phenotyping and lymphoproliferation assays. Lymphocytes from healthy donors and patients were exposed to tumor culture supernatants to evaluate apoptosis induced by the tumor microenvironment. Results showed that HPV-positive tumors exhibited lower T lymphocyte frequencies compared to HPV-negative tumors. Additionally, patients infected with high-risk HPV demonstrated reduced maturation rates of Mo-DCs and decreased expression of co-stimulatory molecules on these cells compared to healthy donors. Furthermore, Mo-DCs from hrHPV-positive patients showed impaired lymphoproliferation capacity relative to controls, while HPV-negative patients exhibited a trend towards reduced lymphoproliferative ability. Regarding the simulated tumor microenvironment, lymphocytes from healthy donors underwent apoptosis, contrasting with patients' lymphocytes, which showed increased viability when cultured with tumor supernatants. These results underscore the impact of HPV infection on T lymphocyte infiltration, Mo-DC maturation, and lymphocyte survival in PSCC, offering critical insights for advancing our understanding of the tumor microenvironment and guiding the development of immunotherapy strategies.

Polygonatum sibiricum Polysaccharide Inhibited Liver Cancer in a Simulated Tumor Microenvironment by Eliminating TLR4/STAT3 Pathway.

Liver cancer is one of the most aggressive tumors and one of the most common malignant tumors which seriously threatens human health. Traditional Chinese medicine (TCM) was reported to resist the proliferation and metastasis of liver cancer cells. In this study, we aimed to explore the potential anti-cancer effect of Polygonatum sibiricum polysaccharide (PSP) on the tumor immune microenvironment in liver cancer cells. HepG2 and Hep3B cells were pretreated in the absence or the presence of PSP (20, 50, 100 µg/mL) for a period of 24 h. Subsequently, dendritic cells (DCs) were co-cultured with HepG2 and Hep3B cell supernatant to investigate the effect of PSP on the tumor microenvironment. The results showed that PSP dose-dependently inhibited proliferation and promoted apoptosis of HepG2 and Hep3B cells. Meanwhile, PSP dose-dependently inhibited migration, invasion, and epithelial-to-mesenchymal transition (EMT) of liver cancer cells. In addition, PSP dose-dependently induced inflammatory response of DCs, characterized by increases of interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α in DCs. Mechanically, PSP dose-dependently reduced the activation of the Toll-like receptor 4 (TLR4)/Signal transducer and activator of transcription 3 (STAT3) and noncanonical nuclear factor-kappa B (NF-κB) signaling pathways. TLR4 agonist lipopolysaccharide (LPS) reversed the anti-oncogenic effects of PSP in liver cancer cells. Taken together, PSP inhibited liver cancer in a simulated tumor microenvironment by eliminating TLR4/STAT3 pathway. PSP promises an important and useful alternative to liver cancer treatment.

Self-assembly of Hyaluronic Acid-Cu-Quercetin flavonoid nanoparticles: synergistic chemotherapy to target tumors.

In this study, a natural compound quercetin (Qu) was investigated for its various antitumor effects. However, due to its poor water solubility and low bioavailability, its clinical application is limited. To overcome this constraint, a modification was to Qu, which resulted in the creation of novel flavonoid self-assembling nanoparticles (HCQ NPs). HCQ NPs were synthesized by a self-assembly method and characterized using transmission electron microscopy, the Malvern Zetasizer instrument, X-ray photoelectron spectroscopy (XPS), the ultraviolet-visible spectrophotometric method (UV-vis), Fourier transform infrared (FITR) and inductively coupled plasma mass spectrometry. Extracellular, methylene blue spectrophotometric analysis was used to determine the ability of HCQ NPs to react with different concentrations of H2O2 to form hydroxyl radicals (•OH). Intracellular, DCFH-DA staining was used to detect the ability of HCQ NPs to react with H2O2 to generate reactive oxygen species. Flow cytometry was used to detect the uptake of HCQ NPs by MDA-MB-231 cells at different time points. The biocompatibility of HCQ NPs was evaluated using the Cell Counting Kit-8 (CCK-8) assay. Calcein AM/PI double staining and the CCK-8 assay were used to evaluate the synergistic antitumor effect of HCQ NPs and H2O2. HCQ NPs showed uniformly sized analogous spherical shapes with a hydrodynamic diameter of 55.36 ± 0.27 nm. XPS revealed that Cu was mainly present as Cu2+ in the HCQ NPs. UV-vis absorption spectrum of the characteristic peak of HCQ NPs was located at 296 nm. Similarly, FTIR spectroscopy revealed a complex formation of Qu and Cu2+ that substantially changed the wavenumber of the 4-position C = O characteristic absorption peak. Based on the proportion of Qu and Cu2+ (1:2), the total drug loading of Qu and Cu2+ in the HCQ NPs for therapeutic purposes was calculated to be 9%. Methylene blue spectrophotometric analysis of •OH indicated that Cu can lead to the generation of •OH by triggering Fenton-like reactions. HCQ NPs rapidly accumulated in MDA-MB-231 cells with the extension of time, and the maximum accumulation concentration was reached at about 0.5 h. Calcein AM/PI double staining and CCK-8 revealed synergistic antitumor effects of HCQ NPs including the chemotherapeutic effect of Qu and chemodynamic therapy by Cu2+ in a simulated tumor microenvironment. HCQ NPs demonstrated very low toxicity in LO2 cells in the biocompatibility experiment. This study show cases a new method of creating self-assembled flavonoid HCQ NPs that show great for fighting cancer.

10-hydroxycamptothecin-loaded starch-based microcapsules with the stepwise responsive release strategy for targeted controlled release

Controlled and accurate drug release at the target site have been the focus of research. Especially in cancer therapy, economical, convenient and accurate delivery strategies could help to reduce the toxic effects of drugs on normal tissues and improve drug availability. In the study, glutathione (GSH)-responsive microcapsules (FA-RSMCs) were prepared by sonochemical method based on thiolated modified starch. 10-Hydroxycamptothecin (HCPT) was designed as a reactive oxygen species (ROS)-responsive polyprodrug (polyHCPT), which was loaded into the core of the microcapsules to obtain stepwise released drug delivery carriers. In the tumor microenvironment, FA-RSMCs first triggered GSH-responsive cleavage to release polyHCPT, followed by ROS-responsive cleavage of polyHCPT to release intact HCPT drug molecules. The results of experiments in simulated tumor microenvironment showed that FA-RSMCs exhibited good cascade-response release properties in vitro. It exhibited good anti-tumor ability and protection of normal cells in cytotoxicity in vitro. This strategy enhanced the accuracy and safety of targeted delivery of HCPT via microcapsules, which has potential for clinical application.

MiR-342-5p promotes vascular smooth muscle cell phenotypic transition through a negative-feedback regulation of Notch signaling via targeting FOXO3

AimUnder various pathological conditions such as cancer, vascular smooth muscle cells (vSMCs) transit their contractile phenotype into phenotype(s) characterized by proliferation and secretion, a process called vSMC phenotypic transition (vSMC-PT). Notch signaling regulates vSMC development and vSMC-PT. This study aims to elucidate how the Notch signal is regulated. Main methodsGene-modified mice with a SM22α-CreERT2 transgene were generated to activate/block Notch signaling in vSMCs. Primary vSMCs and MOVAS cells were cultured in vitro. RNA-seq, qRT-PCR and Western blotting were used to evaluated gene expression level. EdU incorporation, Transwell and collagen gel contraction assays were conducted to determine the proliferation, migration and contraction, respectively. Key findingsNotch activation upregulated, while Notch blockade downregulated, miR-342-5p and its host gene Evl in vSMCs. However, miR-342-5p overexpression promoted vSMC-PT as shown by altered gene expression profile, increased migration and proliferation, and decreased contraction, while miR-342-5p blockade exhibited the opposite effects. Moreover, miR-342-5p overexpression significantly suppressed Notch signaling, and Notch activation partially abolished miR-342-5p-induced vSMC-PT. Mechanically, miR-342-5p directly targeted FOXO3, and FOXO3 overexpression rescued miR-342-5p-induced Notch repression and vSMC-PT. In a simulated tumor microenvironment, miR-342-5p was upregulated by tumor cell-derived conditional medium (TCM), and miR-342-5p blockade abrogated TCM-induced vSMC-PT. Meanwhile, conditional medium from miR-342-5p-overexpressing vSMCs significantly enhanced tumor cell proliferation, while miR-342-5p blockade had the opposite effects. Consistently, in a co-inoculation tumor model, miR-342-5p blockade in vSMCs significantly delayed tumor growth. SignificancemiR-342-5p promotes vSMC-PT through a negative-feedback regulation of Notch signaling via downregulating FOXO3, which could be a potential target for cancer therapy.

Biodegradable Imprinted Polymer Based on ZIF-8/DOX-HA for Synergistically Targeting Prostate Cancer Cells and Controlled Drug Release with Multiple Responses

Improving the drug loading and delivery efficiency of biodegradable nanomaterials used for targeting prostate cancer (PCa) remains a challenging task. To accomplish this task, herein, a new surface molecularly imprinted polymer (ZIF-8/DOX-HA@MIP) was designed and constructed with a hyaluronic acid (HA)-modified zeolitic imidazolate framework-8 (ZIF-8) metal-organic framework loaded with doxorubicin (DOX) as a substrate and a responsive molecularly imprinted polymer film as a shell. Owing to the large surface area of ZIF-8, DOX was successfully loaded into the ZIF-8/DOX-HA@MIP with a high drug loading efficiency (more than 88%). In vitro cell experiments have shown that the strengthened targeting ability of ZIF-8/DOX-HA@MIP to PCa cells was realized through the synergistic effect of HA and the molecularly imprinted membrane. Under the condition of simulated tumor microenvironment solution, Zn species were released and the particle size of ZIF-8/DOX-HA@MIP decreased gradually by the synergistic effect of hyaluronidase, pH, and glutathione, showing excellent biodegradability. In vivo antitumor research indicated the excellent antitumor activity and biocompatibility of ZIF-8/DOX-HA@MIP. The multifunctional ZIF-8/DOX-HA@MIP constructed herein provides a novel impetus for the development of targeted drug delivery in PCa treatment and a new strategy for treating other tumors.

Dual pH-/Thermoresponsive Shell-Cross-Linked Magnetic Mesoporous Nanospheres for Doxorubicin Delivery and In Vitro/In Vivo Cancer Treatment

Engineered nanomaterials have been explored for chemotherapeutic drug delivery systems toward improved therapeutic effects. In this study, magnetic nanospheres consisting of MCM-41 formed onto iron oxide nanoparticles (MIO NPs) to form MMCM with cross-linked shells of Pluronic F127 (PF) and polyethylenimine (PEI) to form (MMFPEI NSs) nanospheres were synthesized. These nanospheres were loaded with doxorubicin (DOX) anticancer drug for drug-controlled release and therapeutic efficacy evaluations in mice. Nanoscale/core–shell MMFPEI NSs were successfully formed as indicated by the TEM analysis. The microstructural analysis revealed the presence of three peaks corresponding to indexed reflections (100), (110), and (200) of MCM-41. The MMFPEI NSs displayed a pH-/thermoresponsive drug release of 84.76% under a simulated tumor microenvironment. Principally, the Peppas-Sahlin, Weibull, and Korsmeyer-Peppas models, respectively, provided the best fitting for our drug delivery system with the highest correlation degree of coefficient (R2) and the lowest AIC. The kinetics studies for diffusion exponent indicated that the MMFPEI NSs possessed predominantly Fickian diffusion behavior. The growth retardation results of HepG2 cells showed that when compared with free DOX, the MMFPEI-DOX NSs exhibited statistically significant stronger cell inhibition efficacy at the dosages of 2, 5, and 10 μg/mL after 24 and 48 h of incubation. According to the in vivo therapeutic assessments, the tumor sizes upon inoculation with PBS, MMFPEI NSs, PBS-DOX, and MMFPEI-DOX NSs were 1302.7, 1165.6, 830.9, and 382.6 mm3, respectively. Therefore, the formulated nanospheres have great probable for drug delivery in cancer therapy to overcome the limits of traditional chemotherapy.

Glucosamine-Modified Reduction-Responsive Polymeric Micelles for Liver Cancer Therapy.

In this work, glucose transporter-1 (GLUT-1) and glutathione (GSH) over-expression in liver cancer was utilized to design a reduction-responsive and active targeting drug delivery system AG-PEG-SS-PCL (APSP) for the delivery of sorafenib (SF). The SF-APSP micelles were prepared using the thin film hydration method and characterized by various techniques. In vitro release experiments showed that the cumulative release of SF-APSP micelles in the simulated tumor microenvironment (pH 7.4 with GSH) reached 94.76 ± 1.78% at 48 h, while it was only 20.32 ± 1.67% in the normal physiological environment (pH 7.4 without GSH). The in vitro study revealed that glucosamine (AG) enhanced the antitumor effects of SF, and SF-APSP micelles inhibited proliferation by targeting HepG2 cells and suppressing cyclin D1 expression. The in vivo antitumor efficacy study further confirmed that the SF-APSP micelles had excellent antitumor effects and better tolerance against nude mouse with HepG2 cells than other treatment groups. All in all, these results indicated that SF-APSP micelles could be a promising drug delivery system for anti-hepatoma treatment.

New insights about the intercalation of 5-Fluorouracil into 2D Mg–Al layered double hydroxide nanosheets: A theoretical and experimental investigation

Layered double hydroxides (LDH) are interesting 2D inorganic platforms for biomedical purposes. In contrast to previous studies, this work reports the intercalation of 5-Fluorouracil (5-FU) into LDH through anion exchange using a fresh LDH material without the need for any organic compound or treatment prior to the intercalation with 5-FU. The combination of experimental charaterizations and computational studies allowed us to study the intercalation process, where the presence of three phases in the hybrid material are suggested: two of them are related to different charge states of the intercalated 5-FU into 2D LDH interlayer space, and the third one might be related to some kind of distorted LDH. FTIR, XPS and DFT calculations indicated that interactions established in the host-guest system involve a complex network of hydrogen bonds, contributing to the improvement of the chemical and thermal stability of the 5-FU-LDH hybrid. Release assays of 5-FU from the 5-FU-LDH demonstrated the ability to selectively release the drug in simulated tumor microenvironment, while in vitro bioassays suggested a dose-dependent behavior of the hybrid. These results contribute to a better understanding of the chemistry of intercalation of 5-FU into 2D-LDH, and can be used to tune properties of 5-FU-LDH in antitumor therapy.

Integration of chemotherapy and phototherapy based on a pH/ROS/NIR multi-responsive polymer-modified MSN drug delivery system for improved antitumor cells efficacy

Due to the difference of the intracellular microenvironment between tumor and normal cells, many stimuli-responsive drug carriers have been developed for precise drug delivery and improved treatment effect. In this paper, a multi responsive drug delivery system based on mesoporous silica nanoparticle (MSN) was prepared. A pH/ROS-sensitive polymer was designed and used to attach to the MSN surface, which acted as a smart nano-valve to prevent premature leakage of drugs. The carrier has been proved to release drugs selectively in simulated tumor microenvironment with lower pH and higher ROS content. And, by co-loading a photosensitizer with antitumor drug, the carrier could produce exogenous ROS under the near-infrared light irradiation, resulting in much quicker removing of the polymer and more drug release. Furtherly, the antitumor effect was evaluated by CCK-8 assay using normal and tumor liver cells. In short, the results of drug release and cell experiments both showed that the carriers had excellent anti-tumor cells effects.

Stiffness-Transformable Nanoplatforms Responsive to the Tumor Microenvironment for Enhanced Tumor Therapeutic Efficacy.

Herein, we report, for the first time, a unique stiffness-transformable manganese oxide hybridized mesoporous organosilica nanoplatform (MMON) for enhancing tumor therapeutic efficacy. The prepared MMONs had a quasi-spherical morphology and were completely transformed into soft bowl-like nanocapsules in the simulated tumor microenvironment through the breakage of Mn-O bonds, which decreased their Young's modulus from 165.7 to 84.5 MPa. Due to their unique stiffness transformation properties, the MMONs had reduced macrophage internalization, improved tumor cell uptake, and enhanced penetration of multicellular spheroids. In addition, in vivo experiments showed that the MMONs displayed a 3.79- and 2.90-fold decrease in non-specific liver distribution and a 2.87- and 1.83-fold increase in tumor accumulation compared to their soft and stiff counterparts, respectively. Furthermore, chlorin e6 (Ce6) modified MMONs had significantly improved photodynamic therapeutic effect.

Stiffness‐Transformable Nanoplatforms Responsive to the Tumor Microenvironment for Enhanced Tumor Therapeutic Efficacy

AbstractHerein, we report, for the first time, a unique stiffness‐transformable manganese oxide hybridized mesoporous organosilica nanoplatform (MMON) for enhancing tumor therapeutic efficacy. The prepared MMONs had a quasi‐spherical morphology and were completely transformed into soft bowl‐like nanocapsules in the simulated tumor microenvironment through the breakage of Mn−O bonds, which decreased their Young's modulus from 165.7 to 84.5 MPa. Due to their unique stiffness transformation properties, the MMONs had reduced macrophage internalization, improved tumor cell uptake, and enhanced penetration of multicellular spheroids. In addition, in vivo experiments showed that the MMONs displayed a 3.79‐ and 2.90‐fold decrease in non‐specific liver distribution and a 2.87‐ and 1.83‐fold increase in tumor accumulation compared to their soft and stiff counterparts, respectively. Furthermore, chlorin e6 (Ce6) modified MMONs had significantly improved photodynamic therapeutic effect.

Multifunctional porous microspheres encapsulating oncolytic bacterial spores and their potential for cancer immunotherapy.

Clostridium novyi-NT (C. novyi-NT) is an anaerobic bacterium that can be used for targeted cancer therapy because it germinates selectively in the hypoxic regions of tumor tissues. However, systemic administration of C. novyi-NT spores cannot effectively treat tumors because of the limited intratumoral delivery of active spores. In this study, we demonstrated that multifunctional porous microspheres (MPMs) containing C. novyi-NT spores have the potential for image-guided local tumor therapy. The MPMs can be repositioned under an external magnetic field, enabling precise tumor targeting and retention. Polylactic acid-based MPMs were prepared using the oil-in-water emulsion technique and then coated with a cationic polyethyleneimine polymer prior to loading with negatively charged C. novyi-NT spores. The C. novyi-NT spores delivered by MPMs were released and germinated in a simulated tumor microenvironment, effectively secreting proteins cytotoxic to tumor cells. In addition, the germinated C. novyi-NT induced immunogenic death of the tumor cells and M1 polarization of macrophages. These results indicate that MPMs encapsulated with C. novyi-NT spores have great potential for image-guided cancer immunotherapy.